xref: /dragonfly/sbin/rcorder/rcorder.c (revision 0de61e28)
1 /*
2  * Copyright (c) 1998, 1999 Matthew R. Green
3  * All rights reserved.
4  * Copyright (c) 1998
5  * 	Perry E. Metzger.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *	This product includes software developed for the NetBSD Project
18  *	by Perry E. Metzger.
19  * 4. The name of the author may not be used to endorse or promote products
20  *    derived from this software without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  *
33  *	$NetBSD: rcorder.c,v 1.7 2000/08/04 07:33:55 enami Exp $
34  */
35 
36 #include <sys/types.h>
37 #include <sys/stat.h>
38 
39 #include <err.h>
40 #include <stdbool.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <unistd.h>
45 #include <libutil.h>
46 
47 #include "sprite.h"
48 #include "hash.h"
49 
50 #ifdef DEBUG
51 static int debug = 0;
52 # define	DPRINTF(args) if (debug) { fflush(stdout); fprintf args; }
53 #else
54 # define	DPRINTF(args)
55 #endif
56 
57 #define REQUIRE_STR	"# REQUIRE:"
58 #define REQUIRE_LEN	(sizeof(REQUIRE_STR) - 1)
59 #define REQUIRES_STR	"# REQUIRES:"
60 #define REQUIRES_LEN	(sizeof(REQUIRES_STR) - 1)
61 #define PROVIDE_STR	"# PROVIDE:"
62 #define PROVIDE_LEN	(sizeof(PROVIDE_STR) - 1)
63 #define PROVIDES_STR	"# PROVIDES:"
64 #define PROVIDES_LEN	(sizeof(PROVIDES_STR) - 1)
65 #define BEFORE_STR	"# BEFORE:"
66 #define BEFORE_LEN	(sizeof(BEFORE_STR) - 1)
67 #define KEYWORD_STR	"# KEYWORD:"
68 #define KEYWORD_LEN	(sizeof(KEYWORD_STR) - 1)
69 #define KEYWORDS_STR	"# KEYWORDS:"
70 #define KEYWORDS_LEN	(sizeof(KEYWORDS_STR) - 1)
71 
72 static int exit_code;
73 static int file_count;
74 static char **file_list;
75 
76 typedef bool flag;
77 #define SET true
78 #define RESET false
79 
80 static Hash_Table provide_hash_s, *provide_hash;
81 
82 typedef struct provnode provnode;
83 typedef struct filenode filenode;
84 typedef struct f_provnode f_provnode;
85 typedef struct f_reqnode f_reqnode;
86 typedef struct strnodelist strnodelist;
87 
88 struct provnode {
89 	flag		head;
90 	flag		in_progress;
91 	filenode	*fnode;
92 	provnode	*next, *last;
93 	char		*name;
94 };
95 
96 struct f_provnode {
97 	provnode	*pnode;
98 	f_provnode	*next;
99 };
100 
101 struct f_reqnode {
102 	Hash_Entry	*entry;
103 	f_reqnode	*next;
104 };
105 
106 struct strnodelist {
107 	filenode	*node;
108 	strnodelist	*next;
109 	char		s[1];
110 };
111 
112 struct filenode {
113 	char		*filename;
114 	flag		in_progress;
115 	filenode	*next, *last;
116 	f_reqnode	*req_list;
117 	f_provnode	*prov_list;
118 	strnodelist	*keyword_list;
119 };
120 
121 static filenode fn_head_s, *fn_head;
122 
123 static strnodelist *bl_list;
124 static strnodelist *keep_list;
125 static strnodelist *skip_list;
126 static strnodelist *onetime_list;
127 
128 static int provide;
129 
130 static void do_file(filenode *fnode);
131 static void strnode_add(strnodelist **, char *, filenode *);
132 static int skip_ok(filenode *fnode);
133 static int keep_ok(filenode *fnode);
134 static void satisfy_req(f_reqnode *rnode, char *filename);
135 static void crunch_file(char *);
136 static void parse_require(filenode *, char *);
137 static void parse_provide(filenode *, char *);
138 static void parse_before(filenode *, char *);
139 static void parse_keywords(filenode *, char *);
140 static filenode *filenode_new(char *);
141 static void add_require(filenode *, char *);
142 static void add_provide(filenode *, char *);
143 static void add_before(filenode *, char *);
144 static void add_keyword(filenode *, char *);
145 static void insert_before(void);
146 static Hash_Entry *make_fake_provision(filenode *);
147 static void crunch_all_files(void);
148 static void initialize(void);
149 static void generate_ordering(void);
150 
151 int
152 main(int argc, char **argv)
153 {
154 	int ch;
155 
156 	while ((ch = getopt(argc, argv, "dpk:s:o:")) != -1)
157 		switch (ch) {
158 		case 'd':
159 #ifdef DEBUG
160 			debug = 1;
161 #else
162 			warnx("debugging not compiled in, -d ignored");
163 #endif
164 			break;
165 		case 'k':
166 			strnode_add(&keep_list, optarg, 0);
167 			break;
168 		case 's':
169 			strnode_add(&skip_list, optarg, 0);
170 			break;
171 		case 'o':
172 			strnode_add(&onetime_list, optarg, 0);
173 			break;
174 		case 'p':
175 			provide = 1;
176 			break;
177 		default:
178 			/* XXX should crunch it? */
179 			break;
180 		}
181 	argc -= optind;
182 	argv += optind;
183 
184 	file_count = argc;
185 	file_list = argv;
186 
187 	DPRINTF((stderr, "parse_args\n"));
188 	initialize();
189 	DPRINTF((stderr, "initialize\n"));
190 	crunch_all_files();
191 	DPRINTF((stderr, "crunch_all_files\n"));
192 	generate_ordering();
193 	DPRINTF((stderr, "generate_ordering\n"));
194 
195 	exit(exit_code);
196 }
197 
198 /*
199  * initialise various variables.
200  */
201 static void
202 initialize(void)
203 {
204 
205 	fn_head = &fn_head_s;
206 
207 	provide_hash = &provide_hash_s;
208 	Hash_InitTable(provide_hash, file_count);
209 }
210 
211 /* generic function to insert a new strnodelist element */
212 static void
213 strnode_add(strnodelist **listp, char *s, filenode *fnode)
214 {
215 	strnodelist *ent;
216 
217 	ent = emalloc(sizeof *ent + strlen(s));
218 	ent->node = fnode;
219 	strcpy(ent->s, s);
220 	ent->next = *listp;
221 	*listp = ent;
222 }
223 
224 /*
225  * below are the functions that deal with creating the lists
226  * from the filename's given dependencies and provisions
227  * in each of these files.  no ordering or checking is done here.
228  */
229 
230 /*
231  * we have a new filename, create a new filenode structure.
232  * fill in the bits, and put it in the filenode linked list
233  */
234 static filenode *
235 filenode_new(char *filename)
236 {
237 	filenode *temp;
238 
239 	temp = emalloc(sizeof(*temp));
240 	memset(temp, 0, sizeof(*temp));
241 	temp->filename = estrdup(filename);
242 	temp->req_list = NULL;
243 	temp->prov_list = NULL;
244 	temp->keyword_list = NULL;
245 	temp->in_progress = RESET;
246 	/*
247 	 * link the filenode into the list of filenodes.
248 	 * note that the double linking means we can delete a
249 	 * filenode without searching for where it belongs.
250 	 */
251 	temp->next = fn_head->next;
252 	if (temp->next != NULL)
253 		temp->next->last = temp;
254 	temp->last = fn_head;
255 	fn_head->next = temp;
256 	return (temp);
257 }
258 
259 /*
260  * add a requirement to a filenode.
261  */
262 static void
263 add_require(filenode *fnode, char *s)
264 {
265 	Hash_Entry *entry;
266 	f_reqnode *rnode;
267 	int new;
268 
269 	entry = Hash_CreateEntry(provide_hash, s, &new);
270 	if (new)
271 		Hash_SetValue(entry, NULL);
272 	rnode = emalloc(sizeof(*rnode));
273 	rnode->entry = entry;
274 	rnode->next = fnode->req_list;
275 	fnode->req_list = rnode;
276 }
277 
278 /*
279  * add a provision to a filenode.  if this provision doesn't
280  * have a head node, create one here.
281  */
282 static void
283 add_provide(filenode *fnode, char *s)
284 {
285 	Hash_Entry *entry;
286 	f_provnode *f_pnode;
287 	provnode *pnode, *head;
288 	int new;
289 
290 	entry = Hash_CreateEntry(provide_hash, s, &new);
291 	head = Hash_GetValue(entry);
292 
293 	/* create a head node if necessary. */
294 	if (head == NULL) {
295 		head = emalloc(sizeof(*head));
296 		head->head = SET;
297 		head->in_progress = RESET;
298 		head->fnode = NULL;
299 		head->last = head->next = NULL;
300 		Hash_SetValue(entry, head);
301 	}
302 #if 0
303 	/*
304 	 * Don't warn about this.  We want to be able to support
305 	 * scripts that do two complex things:
306 	 *
307 	 *	- Two independent scripts which both provide the
308 	 *	  same thing.  Both scripts must be executed in
309 	 *	  any order to meet the barrier.  An example:
310 	 *
311 	 *		Script 1:
312 	 *
313 	 *			PROVIDE: mail
314 	 *			REQUIRE: LOGIN
315 	 *
316 	 *		Script 2:
317 	 *
318 	 *			PROVIDE: mail
319 	 *			REQUIRE: LOGIN
320 	 *
321 	 * 	- Two interdependent scripts which both provide the
322 	 *	  same thing.  Both scripts must be executed in
323 	 *	  graph order to meet the barrier.  An example:
324 	 *
325 	 *		Script 1:
326 	 *
327 	 *			PROVIDE: nameservice dnscache
328 	 *			REQUIRE: SERVERS
329 	 *
330 	 *		Script 2:
331 	 *
332 	 *			PROVIDE: nameservice nscd
333 	 *			REQUIRE: dnscache
334 	 */
335 	else if (new == 0) {
336 		warnx("file `%s' provides `%s'.", fnode->filename, s);
337 		warnx("\tpreviously seen in `%s'.",
338 		    head->next->fnode->filename);
339 	}
340 #endif
341 
342 	pnode = emalloc(sizeof(*pnode));
343 	pnode->head = RESET;
344 	pnode->in_progress = RESET;
345 	pnode->fnode = fnode;
346 	pnode->next = head->next;
347 	pnode->last = head;
348 	pnode->name = strdup(s);
349 	head->next = pnode;
350 	if (pnode->next != NULL)
351 		pnode->next->last = pnode;
352 
353 	f_pnode = emalloc(sizeof(*f_pnode));
354 	f_pnode->pnode = pnode;
355 	f_pnode->next = fnode->prov_list;
356 	fnode->prov_list = f_pnode;
357 }
358 
359 /*
360  * put the BEFORE: lines to a list and handle them later.
361  */
362 static void
363 add_before(filenode *fnode, char *s)
364 {
365 	strnodelist *bf_ent;
366 
367 	bf_ent = emalloc(sizeof *bf_ent + strlen(s));
368 	bf_ent->node = fnode;
369 	strcpy(bf_ent->s, s);
370 	bf_ent->next = bl_list;
371 	bl_list = bf_ent;
372 }
373 
374 /*
375  * add a key to a filenode.
376  */
377 static void
378 add_keyword(filenode *fnode, char *s)
379 {
380 
381 	strnode_add(&fnode->keyword_list, s, fnode);
382 }
383 
384 /*
385  * loop over the rest of a REQUIRE line, giving each word to
386  * add_require() to do the real work.
387  */
388 static void
389 parse_require(filenode *node, char *buffer)
390 {
391 	char *s;
392 
393 	while ((s = strsep(&buffer, " \t\n")) != NULL)
394 		if (*s != '\0')
395 			add_require(node, s);
396 }
397 
398 /*
399  * loop over the rest of a PROVIDE line, giving each word to
400  * add_provide() to do the real work.
401  */
402 static void
403 parse_provide(filenode *node, char *buffer)
404 {
405 	char *s;
406 
407 	while ((s = strsep(&buffer, " \t\n")) != NULL)
408 		if (*s != '\0')
409 			add_provide(node, s);
410 }
411 
412 /*
413  * loop over the rest of a BEFORE line, giving each word to
414  * add_before() to do the real work.
415  */
416 static void
417 parse_before(filenode *node, char *buffer)
418 {
419 	char *s;
420 
421 	while ((s = strsep(&buffer, " \t\n")) != NULL)
422 		if (*s != '\0')
423 			add_before(node, s);
424 }
425 
426 /*
427  * loop over the rest of a KEYWORD line, giving each word to
428  * add_keyword() to do the real work.
429  */
430 static void
431 parse_keywords(filenode *node, char *buffer)
432 {
433 	char *s;
434 
435 	while ((s = strsep(&buffer, " \t\n")) != NULL)
436 		if (*s != '\0')
437 			add_keyword(node, s);
438 }
439 
440 /*
441  * given a file name, create a filenode for it, read in lines looking
442  * for provision and requirement lines, building the graphs as needed.
443  */
444 static void
445 crunch_file(char *filename)
446 {
447 	FILE *fp;
448 	char *buf;
449 	int require_flag, provide_flag, before_flag, keywords_flag;
450 	enum { BEFORE_PARSING, PARSING, PARSING_DONE } state;
451 	filenode *node;
452 	char delims[3] = { '\\', '\\', '\0' };
453 	struct stat st;
454 
455 	if ((fp = fopen(filename, "r")) == NULL) {
456 		warn("could not open %s", filename);
457 		return;
458 	}
459 
460 	if (fstat(fileno(fp), &st) == -1) {
461 		warn("could not stat %s", filename);
462 		fclose(fp);
463 		return;
464 	}
465 
466 	if (!S_ISREG(st.st_mode)) {
467 #if 0
468 		warnx("%s is not a file", filename);
469 #endif
470 		fclose(fp);
471 		return;
472 	}
473 
474 	node = filenode_new(filename);
475 
476 	/*
477 	 * we don't care about length, line number, don't want # for comments,
478 	 * and have no flags.
479 	 */
480 	for (state = BEFORE_PARSING; state != PARSING_DONE &&
481 	    (buf = fparseln(fp, NULL, NULL, delims, 0)) != NULL; free(buf)) {
482 		require_flag = provide_flag = before_flag = keywords_flag = 0;
483 		if (strncmp(REQUIRE_STR, buf, REQUIRE_LEN) == 0)
484 			require_flag = REQUIRE_LEN;
485 		else if (strncmp(REQUIRES_STR, buf, REQUIRES_LEN) == 0)
486 			require_flag = REQUIRES_LEN;
487 		else if (strncmp(PROVIDE_STR, buf, PROVIDE_LEN) == 0)
488 			provide_flag = PROVIDE_LEN;
489 		else if (strncmp(PROVIDES_STR, buf, PROVIDES_LEN) == 0)
490 			provide_flag = PROVIDES_LEN;
491 		else if (strncmp(BEFORE_STR, buf, BEFORE_LEN) == 0)
492 			before_flag = BEFORE_LEN;
493 		else if (strncmp(KEYWORD_STR, buf, KEYWORD_LEN) == 0)
494 			keywords_flag = KEYWORD_LEN;
495 		else if (strncmp(KEYWORDS_STR, buf, KEYWORDS_LEN) == 0)
496 			keywords_flag = KEYWORDS_LEN;
497 		else {
498 			if (state == PARSING)
499 				state = PARSING_DONE;
500 			continue;
501 		}
502 
503 		state = PARSING;
504 		if (require_flag)
505 			parse_require(node, buf + require_flag);
506 		else if (provide_flag)
507 			parse_provide(node, buf + provide_flag);
508 		else if (before_flag)
509 			parse_before(node, buf + before_flag);
510 		else if (keywords_flag)
511 			parse_keywords(node, buf + keywords_flag);
512 	}
513 	fclose(fp);
514 }
515 
516 static Hash_Entry *
517 make_fake_provision(filenode *node)
518 {
519 	Hash_Entry *entry;
520 	f_provnode *f_pnode;
521 	provnode *head, *pnode;
522 	static	int i = 0;
523 	int	new;
524 	char buffer[30];
525 
526 	do {
527 		snprintf(buffer, sizeof buffer, "fake_prov_%08d", i++);
528 		entry = Hash_CreateEntry(provide_hash, buffer, &new);
529 	} while (new == 0);
530 	head = emalloc(sizeof(*head));
531 	head->head = SET;
532 	head->in_progress = RESET;
533 	head->fnode = NULL;
534 	head->last = head->next = NULL;
535 	Hash_SetValue(entry, head);
536 
537 	pnode = emalloc(sizeof(*pnode));
538 	pnode->head = RESET;
539 	pnode->in_progress = RESET;
540 	pnode->fnode = node;
541 	pnode->next = head->next;
542 	pnode->last = head;
543 	pnode->name = strdup(buffer);
544 	head->next = pnode;
545 	if (pnode->next != NULL)
546 		pnode->next->last = pnode;
547 
548 	f_pnode = emalloc(sizeof(*f_pnode));
549 	f_pnode->pnode = pnode;
550 	f_pnode->next = node->prov_list;
551 	node->prov_list = f_pnode;
552 
553 	return (entry);
554 }
555 
556 /*
557  * go through the BEFORE list, inserting requirements into the graph(s)
558  * as required.  in the before list, for each entry B, we have a file F
559  * and a string S.  we create a "fake" provision (P) that F provides.
560  * for each entry in the provision list for S, add a requirement to
561  * that provisions filenode for P.
562  */
563 static void
564 insert_before(void)
565 {
566 	Hash_Entry *entry, *fake_prov_entry;
567 	provnode *pnode;
568 	f_reqnode *rnode;
569 	strnodelist *bl;
570 	int new;
571 
572 	while (bl_list != NULL) {
573 		bl = bl_list->next;
574 
575 		fake_prov_entry = make_fake_provision(bl_list->node);
576 
577 		entry = Hash_CreateEntry(provide_hash, bl_list->s, &new);
578 		if (new == 1 && !provide)
579 			warnx("file `%s' is before unknown provision `%s'",
580 			      bl_list->node->filename, bl_list->s);
581 
582 		for (pnode = Hash_GetValue(entry); pnode; pnode = pnode->next) {
583 			if (pnode->head)
584 				continue;
585 
586 			rnode = emalloc(sizeof(*rnode));
587 			rnode->entry = fake_prov_entry;
588 			rnode->next = pnode->fnode->req_list;
589 			pnode->fnode->req_list = rnode;
590 		}
591 
592 		free(bl_list);
593 		bl_list = bl;
594 	}
595 }
596 
597 /*
598  * loop over all the files calling crunch_file() on them to do the
599  * real work.  after we have built all the nodes, insert the BEFORE:
600  * lines into graph(s).
601  */
602 static void
603 crunch_all_files(void)
604 {
605 	int i;
606 
607 	for (i = 0; i < file_count; i++)
608 		crunch_file(file_list[i]);
609 	insert_before();
610 }
611 
612 /*
613  * below are the functions that traverse the graphs we have built
614  * finding out the desired ordering, printing each file in turn.
615  * if missing requirements, or cyclic graphs are detected, a
616  * warning will be issued, and we will continue on..
617  */
618 
619 /*
620  * given a requirement node (in a filename) we attempt to satisfy it.
621  * we do some sanity checking first, to ensure that we have providers,
622  * aren't already satisfied and aren't already being satisfied (ie,
623  * cyclic).  if we pass all this, we loop over the provision list
624  * calling do_file() (enter recursion) for each filenode in this
625  * provision.
626  */
627 static void
628 satisfy_req(f_reqnode *rnode, char *filename)
629 {
630 	Hash_Entry *entry;
631 	provnode *head;
632 
633 	entry = rnode->entry;
634 	head = Hash_GetValue(entry);
635 
636 	if (head == NULL) {
637 		warnx("requirement `%s' in file `%s' has no providers.",
638 		    Hash_GetKey(entry), filename);
639 		exit_code = 1;
640 		return;
641 	}
642 
643 	/* return if the requirement is already satisfied. */
644 	if (head->next == NULL)
645 		return;
646 
647 	/*
648 	 * if list is marked as in progress,
649 	 *	print that there is a circular dependency on it and abort
650 	 */
651 	if (head->in_progress == SET) {
652 		warnx("Circular dependency on provision `%s' in file `%s'.",
653 		    Hash_GetKey(entry), filename);
654 		exit_code = 1;
655 		return;
656 	}
657 
658 	head->in_progress = SET;
659 
660 	/*
661 	 * while provision_list is not empty
662 	 *	do_file(first_member_of(provision_list));
663 	 */
664 	while (head->next != NULL)
665 		do_file(head->next->fnode);
666 }
667 
668 static int
669 skip_ok(filenode *fnode)
670 {
671 	strnodelist *s;
672 	strnodelist *k;
673 
674 	for (s = skip_list; s; s = s->next)
675 		for (k = fnode->keyword_list; k; k = k->next)
676 			if (strcmp(k->s, s->s) == 0)
677 				return (0);
678 
679 	return (1);
680 }
681 
682 static int
683 keep_ok(filenode *fnode)
684 {
685 	strnodelist *s;
686 	strnodelist *k;
687 
688 	for (s = keep_list; s; s = s->next)
689 		for (k = fnode->keyword_list; k; k = k->next)
690 			if (strcmp(k->s, s->s) == 0)
691 				return (1);
692 
693 	/* an empty keep_list means every one */
694 	return (!keep_list);
695 }
696 
697 /*
698  * given a filenode, we ensure we are not a cyclic graph.  if this
699  * is ok, we loop over the filenodes requirements, calling satisfy_req()
700  * for each of them.. once we have done this, remove this filenode
701  * from each provision table, as we are now done.
702  *
703  * NOTE: do_file() is called recursively from several places and cannot
704  * safely free() anything related to items that may be recursed on.
705  * Circular dependencies will cause problems if we do.
706  */
707 static void
708 do_file(filenode *fnode)
709 {
710 	f_reqnode *r;
711 	f_provnode *p, *p_tmp;
712 	provnode *pnode;
713 	int was_set;
714 
715 	DPRINTF((stderr, "do_file on %s.\n", fnode->filename));
716 
717 	/*
718 	 * if fnode is marked as in progress,
719 	 *	 print that fnode; is circularly depended upon and abort.
720 	 */
721 	if (fnode->in_progress == SET) {
722 		warnx("Circular dependency on file `%s'.",
723 			fnode->filename);
724 		was_set = exit_code = 1;
725 	} else
726 		was_set = 0;
727 
728 	/* mark fnode */
729 	fnode->in_progress = SET;
730 
731 	/*
732 	 * for each requirement of fnode -> r
733 	 *	satisfy_req(r, filename)
734 	 */
735 	r = fnode->req_list;
736 	while (r != NULL) {
737 		satisfy_req(r, fnode->filename);
738 		r = r->next;
739 	}
740 	fnode->req_list = NULL;
741 
742 	/*
743 	 * for each provision of fnode -> p
744 	 *	remove fnode from provision list for p in hash table
745 	 */
746 	p = fnode->prov_list;
747 	while (p != NULL) {
748 		p_tmp = p;
749 		pnode = p->pnode;
750 		if (pnode->next != NULL) {
751 			pnode->next->last = pnode->last;
752 		}
753 		if (pnode->last != NULL) {
754 			pnode->last->next = pnode->next;
755 		}
756 		free(pnode);
757 		p = p->next;
758 		free(p_tmp);
759 	}
760 	fnode->prov_list = NULL;
761 
762 	/* do_it(fnode) */
763 	DPRINTF((stderr, "next do: "));
764 
765 	/* if we were already in progress, don't print again */
766 	if (was_set == 0 && skip_ok(fnode) && keep_ok(fnode))
767 		printf("%s\n", fnode->filename);
768 
769 	if (fnode->next != NULL) {
770 		fnode->next->last = fnode->last;
771 	}
772 	if (fnode->last != NULL) {
773 		fnode->last->next = fnode->next;
774 	}
775 
776 	DPRINTF((stderr, "nuking %s\n", fnode->filename));
777 }
778 
779 static void
780 generate_ordering(void)
781 {
782 
783 	/*
784 	 * while there remain undone files{f},
785 	 *	pick an arbitrary f, and do_file(f)
786 	 * Note that the first file in the file list is perfectly
787 	 * arbitrary, and easy to find, so we use that.
788 	 */
789 
790 	/*
791 	 * N.B.: the file nodes "self delete" after they execute, so
792 	 * after each iteration of the loop, the head will be pointing
793 	 * to something totally different. The loop ends up being
794 	 * executed only once for every strongly connected set of
795 	 * nodes.
796 	 */
797 	if (provide) {
798 		/*
799 		 * List all keywords provided by the listed files
800 		 */
801 		filenode *file;
802 		f_provnode *f_prov;
803 
804 		for (file = fn_head->next; file; file = file->next) {
805 		    for (f_prov = file->prov_list; f_prov; f_prov = f_prov->next) {
806 			if (strncmp(f_prov->pnode->name, "fake_", 5) != 0)
807 			    printf("%s\n", f_prov->pnode->name);
808 		    }
809 		}
810 	} else if (onetime_list) {
811 		/*
812 		 * Only list dependanacies required to start particular
813 		 * keywords.
814 		 */
815 		strnodelist *scan;
816 		filenode *file;
817 		f_provnode *f_prov;
818 
819 		for (scan = onetime_list; scan; scan = scan->next) {
820 		    for (file = fn_head->next; file; file = file->next) {
821 			for (f_prov = file->prov_list; f_prov; f_prov = f_prov->next) {
822 			    if (strcmp(scan->s, f_prov->pnode->name) == 0) {
823 				do_file(file);
824 				break;
825 			    }
826 			}
827 			if (f_prov)
828 			    break;
829 		    }
830 		}
831 	} else {
832 		while (fn_head->next != NULL) {
833 			DPRINTF((stderr, "generate on %s\n",
834 				 fn_head->next->filename));
835 			do_file(fn_head->next);
836 		}
837 	}
838 }
839